PTL 1 discloses the devices illustrated in FIG. 5 as the lower member fixing device and fluid control device covered by the invention.
A fluid control device (1) is used in semiconductor equipment or the like and includes a plurality of block joints (lower members) (2) and (3) having fluid passages opened upward, a plurality of fluid control units (upper members) (4), (5), (6), and (7) having fluid passages opened downward and communicating with the fluid passages of the block joints (2) and (3), a plurality of sealing sections (not illustrated) provided on an abutting surface between the fluid passages of the block joints (2) and (3) and the fluid passages provided in the main bodies (4a), (5a), (6a), and (7a) of the fluid control units (4), (5), (6), and (7), a support member (51) for supporting the plurality of block joints (2) and (3), a plurality of joint member fixing bolts (52) for securing the block joints (2) and (3) to the support member (51), and a plurality of fluid control unit fixing bolts (8) for securing the fluid control units (4), (5), (6), and (7) to the block joints (2) and (3).
Each of the block joints (2) and (3) has a through hole (11) through which a bolt is inserted, a cylindrical spacer (12) is inserted into the through hole (11), and an annular elastic member (13) for biasing the block joints (2) and (3) downward (toward the support member (51)) is disposed on the lower surface of the flange of the spacer (12).
A lower member fixing device (9) fixes the block joints (2) and (3) (that is, lower members (2) and (3) with the through hole (11)) disposed between the support member (51) and the upper members (4), (5), (6), and (7) to the support member (51) and includes a screw hole (51a) provided in the support member (51), the bolt (52), the spacer (12), the elastic member (13), and the like.